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authorMarek Marczykowski-Górecki <marmarek@invisiblethingslab.com>2017-06-26 14:49:46 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-07-27 15:06:06 -0700
commit5c7c179eb9e30e978180fdb1ca0833593221b4e5 (patch)
treee4e55253e235ca4c936402824d046bf3ec9a3839 /arch
parent78dce99f5497468e3f4e9de4e08c2b1db6c4b2e1 (diff)
downloadlinux-linaro-stable-5c7c179eb9e30e978180fdb1ca0833593221b4e5.tar.gz
x86/xen: allow userspace access during hypercalls
commit c54590cac51db8ab5fd30156bdaba34af915e629 upstream. Userspace application can do a hypercall through /dev/xen/privcmd, and some for some hypercalls argument is a pointers to user-provided structure. When SMAP is supported and enabled, hypervisor can't access. So, lets allow it. The same applies to HYPERVISOR_dm_op, where additionally privcmd driver carefully verify buffer addresses. Cc: stable@vger.kernel.org Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Reviewed-by: Juergen Gross <jgross@suse.com> [HYPERVISOR_dm_op dropped - not present until 4.11] Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/include/asm/xen/hypercall.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/include/asm/xen/hypercall.h b/arch/x86/include/asm/xen/hypercall.h
index 4c20dd333412..85133b2b8e99 100644
--- a/arch/x86/include/asm/xen/hypercall.h
+++ b/arch/x86/include/asm/xen/hypercall.h
@@ -43,6 +43,7 @@
#include <asm/page.h>
#include <asm/pgtable.h>
+#include <asm/smap.h>
#include <xen/interface/xen.h>
#include <xen/interface/sched.h>
@@ -213,10 +214,12 @@ privcmd_call(unsigned call,
__HYPERCALL_DECLS;
__HYPERCALL_5ARG(a1, a2, a3, a4, a5);
+ stac();
asm volatile("call *%[call]"
: __HYPERCALL_5PARAM
: [call] "a" (&hypercall_page[call])
: __HYPERCALL_CLOBBER5);
+ clac();
return (long)__res;
}